Posts Tagged ‘meteor shower’

The Perseid Meteor Shower 2014

The Perseid Meteor Shower Image Credit :- Astronomy Picture of the Day

The Perseids are one of the most prolific and best-known of the meteor showers and the Perseid Meteor Shower can be seen in late July and through August each year, with the maximum Perseid meteor activity on or around 12/13 August. Read the rest of this entry »

Quadrantid Meteor Shower 2014

Quadrantid Meteor Shower Credit: NASA

The Quadrantid Meteor Shower ushers in 2014 with its peak on the 3rd of January.

The Quadrantids can be an impressive meteor shower with rates of up to 120 meteors per hour at peak (under perfect conditions) and have been known to produce up to 200 meteors per hour. The peak is quite narrow lasting only a few hours, however there will be plenty of meteors to look out for either side of maximum. Read the rest of this entry »

Quadrantid Meteor Shower 2013

Quadrantid Meteor Shower Credit: nasa.org

The Quadrantid Meteor Shower ushers in 2013 with its peak in the early hours of the 3rd of January.

The Quadrantids can be an impressive meteor shower with rates of up to 120 meteors per hour at its peak (under perfect conditions) and have been known to produce rates of up to 200 meteors per hour. The peak is quite narrow lasting only a few hours, however there will be plenty of meteors to look out for either side of maximum. Read the rest of this entry »

On the night of 17/18 November 2011 the Leonids meteor shower reaches its peak. This annual performer is associated with Comet Temple-Tuttle, which orbits the Sun once every 33 years leaving a trail of debris as it goes. Once a year the Earth passes through this trail, and we see a meteor shower.

Leonids 2001

This year’s Leonids shower is hampered by the last quarter Moon which sits just to the right of the radiant of the Leonids, in Leo. Despite this there is good reason to observe the shower this year, as the International Meteor Organisation suggest there might be as many as three peaks of activity.

Throughout November the rate of Leonids will increase, with the main peak occurring at 0340 GMT on 18 November, at which time the Zenith Hourly Rate may be 20+. For observers in the UK, observing under cloudless skies, away from light pollution, this translates as an hourly rate of ~14, but the Moon will interfere and reduce this value somewhat. Two other peaks may also occur, at ~2100 on November 17, and at ~2300 on 18 November, with similar rates. This means that both the nights of 17/18 and 18/19 November may offer good opportunites to observe this shower.

The Leonids has the distinction of being the most dramatic meteor shower that I’ve ever seen, as I observed the Leonid meteor storms every year from 1998 to 2002, when we saw hundreds of meteors each night at the peak of the shower. These storm peaks are predictable, and occur every 33 years, associated with the pass of comet Temple Tuttle, as it refreshes the trail of debris that cause the meteors. The next pass of Temple Tuttle is due 2031, so we’ve a long wait for the next storm.

Interestingly, the Leonid storm of 1833 was truly stunning, with rates estimated to be around 100,000 per hour across North America.

To view the Leonids, find a dark spot, away from light pollution, sit on a reclining deck chair facing as large an area of the sky as you can manage, wrap yourself in a blanket, and enjoy the view. For observers in the UK the meteor shower radiant will rise around 2200 GMT on 17 November and will be high in the SE by 0400 on 18 November.

Some time in the small hours of Friday or Saturday morning (21-22 October 2011) the Orionids meteor shower will reach its peak activity rate. The peak occurs some time around 21 October each year, but this year it’s uncertain which day it will fall on.

The Orionid's parent Comet P/Halley as taken March 8, 1986 by W. Liller, Easter Island, part of the International Halley Watch (IHW) Large Scale Phenomena Network.

Meteor showers result from the Earth passing through the trail of dust and debris left behind by a comet. In the case of the Orionids the parent object is the most famous of all the comets – Halley’s Comet.

The peak meteor rate for the Orionids is lower than some of the more spectacular showers (the Perseids in August, the Geminids in December, and the Quadrantids in January all regularly outperform the Orionids) but it is still worth looking out for.

The meteors will appear to radiate from the constellation of Orion (hence the name) but they will streak across the sky in all directions, and so you shouldn’t confine yourself to only looking towards this one constellation.

On Thursday and Friday evenings the radiant rises in the east around 2200 BST (2100 UT) and continues to rise to its highest in the south just before the sky starts to brighten at 0600 BST (0500 UT). The higher the radiant above the horizon the more meteors you will see. However a crescent Moon will rises in the east on both mornings, the light from which will drown out some of the fainter meteors.

This shouldn’t matter much to you if you’re observing from an urban or suburban area, as the man-made light pollution in the sky will do a far better job of obscuring the meteor shower than the Moon will, but for lucky observers in dark sites (and I’ll be one of them, as I’m spending the weekend on Sark, the world’s first Dark Sky Island) the Moon may interfere.

Here’s a table with estimated hourly rates based on dark skies / suburban / urban areas, at hourly intervals throughout the night, assuming a ZHR =40 throughout this period (It may be that the peak will fall outwith this period, e.g. in daylight hours, so these are best-case-scenario numbers).

Time (BST)

Radiant
Altitude

Radiant
Direction

Hourly Rate
Urban Site

Hourly Rate
Suburban Site

Hourly Rate
Dark Sky Site (if Moon not present)

2200

rises

ENE

<1

<1

<1

2300

8°

ENE

1

2

4

0000

16°

E

1

4

8

0100

24°

ESE

2

6

16

0200

33°

ESE

2

8

22

0300

40°

SE

2

9

26*

0400

46°

SSE

3

10

29*

0500

50°

S

3

11

31*

0600

50°

S

3

11

31*

* the true rates, given that the Moon is causing natural light pollution, are probably half these values.

All of these timings and altitudes are based on an observer in central Scotland. For other UK observers the values in columns 2-4 may be slightly off, but not noticeably so.

Observing Advice: wrap up warm, head out before midnight, sit youself in a reclining lawn chair, and enjoy the spectacle. The rates may pick up around 0200 BST on Thursday or Friday and may stay high until dawn.

The Draconids are coming! Will this meteor shower produce a storm of observable meteors, or just a minor squall? The Draconid Meteor Show should begin on October 8, 2011 starting at dusk (roughly 19:00 BST) and continue through the evening. Peak activity of this normally minor and quiet shower is estimated to be at 21:00 BST (20:00 UT). There seems to be a wide range of predictions for this year’s shower, but some astronomers believe there could be up to 1,000 meteors per hour, making this a meteor storm!Read the rest of this entry »

On Saturday 8 October 2011 a rare event may occur – a meteor storm! The usually sedate Draconids meteor shower only produces a few shooting stars per hour in most years, but in some years we have a meteor storm, and that’s just what’s predicted for this year.

It Won't Look Like This

During a meteor storm the Earth passes through a particularly dense clump of comet dust, meaning that rates of shooting stars temporarily spike, and estimates this time suggest the possibility of up to 10 shooting stars per minute during the peak of the storm. However a nearly full Moon may spoil the view, possibly drowning out all but the brightest meteors, reducing the actual observed rate perhaps 1 per minute – still well worth looking out for.

The peak is set to occur at 2000UT (2100 BST), and is ideally placed for observers in the UK. Activity is expected to increase from 1600UT (1700 BST) but at that stage the sky will still be bright in the UK.

If you’re keen to witness this (possibly) amazing event here are some top tips:

Head out early. Start your meteorwatch once the sky gets dark enough. For most people in the UK this will be from 1900 – 1930 BST (anyone living in the north of Scotland will have to wait a bit longer). Although the peak of the storm is estimated to occur around 2100 BST there will be plenty to see in the hours leading up to the peak.

Know where to look. The Draconids all appear to originate from the constellation Draco, which will be high in the NW sky, just above and to the left of the north star, Polaris. However the meteors will streak across the entire sky so don’t just look NW.

Know what to look for. Meteors appear as bright streaks of light moving rapidly across the sky. They last for a fraction of a second, but the Draconids are unusually slow meteors. Still, blink and you might miss one.

Keep the Moon to your back. The full Moon will drown out the light from all but the brightest Draconids, and if you look at the Moon it will spoil your night vision, so keep it behind you, ideally blocked out by a building or tree.

You just need your eyes. Binoculars and telescopes, while ideal for observing faint nebulae and planets, are no good for meteorwatching. You want to take in as much of the sky as you can, and have as wide a field of view as possible, so just use your eyes.

Get comfortable. The best bit of meteorwatching kit is a reclining lawn chair. Point it towards the NW, lie back, look up and enjoy the show.

Keep warm. It will be very cold outside if it is clear, so wrap up warm. If you’re lying back on a reclining chair, wrap yourself in a blanket or sleeping back form maximum warmth.

Get away from city lights. This isn’t as important for this shower, as the Moon is flooding the sky with natural light anyway, but in general the fewer lights you have around you the better.

Get away from clouds. This hopefully goes without saying, but if your sky is cloudy you won’t see much. The UK Met Office website can tell you if there is a clear sky anywhere near you, and you should consider traveling to get clear skies. You can also check out meteor activity using the Meteor Live View.

Meteor Watch, 2011. Well it’s that time of the year again. The air is warm, days are long, Noctilucent are departing, which can mean only one thing – Meteorwatch is back.

There are many subjects within our night sky that are fascinating to watch and equally challenging to capture on camera. However, there really is something quite exciting and magical about spotting balls of fire streaking across a star filled sky. Maybe my affinity with severe weather and, in particular, lightning was the catalyst for fascination, or perhaps the fact that objects the size of a grain of sand can ironically put on such a grand fireworks display. History, in the form of a meteor shower 200 years ago is said to have inspired Samuel Taylor Coleridge’s lines from his famous poem The Rime of the Ancient Mariner. It’s amazing to think that distant evening, when Coleridge was walking along the Somerset coast witnessing the upper air burst into life, would inspire others as we once again prepare for showers.

Whilst there are many displays throughout the year, the most visible meteor shower is the Perseids which light up the skies around mid August each year and offer peak shows of more than 1 meteor every minute – a perfect viewing event. The moon cycle can invariably weaken the viewing event (depending on phase) but even so the challenge of course is not necessarily to witness but to capture on camera. With this in mind, let us look at some useful pointers which will help camera owners increase their odds of pulling off a meteoric masterpiece over the coming weeks.

Credit: Mark Humpage

Firstly, what Camera Equipment is required? Let’s not pull any punches. To capture a decent meteor image will require a good quality camera. Shooting a subject in low light or darkness will require a camera that allows full manual control of the settings and interchangeable lenses. In this respect a dslr fits the bill perfectly. Talking of lenses, my ideal selection would a choice of two (or both). A wide angle, something in the range of *7-14mm (14-28mm 35mm equivalent) together with a lens to get a bit closer, such as the *12-60mm (24-120mm 35mm equivalent). I’ll talk about why I suggest these two lenses a bit later within the technique section. Another pre-requisite piece of equipment is a tripod. This will give stability for those long exposures, and prevent motion blurring. Finally, I would recommend using a cable release or remote method of triggering the camera shutter. Combined with a tripod for steadying this will minimise camera vibration – you would be surprised how much vibration is created by simply pressing the shutter release button with your finger!

Camera Settings – It’s important not to forget our camera subject which is essentially a fast moving bright object visible for a very short period of time. Successfully capturing a meteor with a short exposure time, in darkness, is near on impossible because timing will be down to luck (extremely low odds) and the foreground (for wide angle shots) will be too dark. In this respect, and to increase our odds of a successful capture we need to use a long exposure time. To do this firstly set the camera to manual mode (M). Now set the exposure time to between 15s and 30s (15s for continuous and 30s for single shooting – I will explain this more in the technique section) and shutter speed to the lowest setting (a good quality lens should get down to F2.8). Set the ISO to 500. This will be good starting point for most cameras. Bear in mind that camera systems and models vary tremendously depending on the technology inside, such as the sensor and processing engine. Personally, I have found 15s-30s is sufficient to capture the duration of a single meteor. Combined with a mid value ISO of around 500 will provide sufficient light to deliver a pleasing image of both foreground and subject whilst keeping noise (grainy effect) to a minimum.

Camera Technique. I must reinforce the fact there is a great element of luck in capturing a meteor on camera. One can advise on the optimum camera equipment and settings but there is never any guarantee of success. The key is not success but rather improving ones odds of success. I can certainly increase your odds and results by using the following techniques, based around lens choice. Firstly and desirably find a location away from populated areas and light pollution. Set up the camera with a Wide Angle Lens and try to position an on object in the foreground, such as a tree or man made structure. This will add perspective or scale to an image. Position the camera/lens to cover the north east skyline keeping a small portion of land in the bottom third or quarter of the frame. Ensure focus is set manually to infinity. Using a 15s exposure time and remote cable (set to lock) pop the camera into sequence shooting and hit the shutter release button (If you don’t have a remote cable simply keep the finger pressed on the shutter release button, although it will get numb quickly!). This effectively primes the camera to take continuous frames until you switch the camera off (or the battery runs out). What you will end up with here is as many (or little) images as desired and which can be imported into stacking software. A final composite image could be as long as the night combining a star trail effect with hopefully a meteor or two. If using this technique a good tip, to improve composition, is choose a foreground subject with something of interest and paint it with light. This can be done simply by setting off a few rounds of flash remotely whilst the camera is shooting or waving a lit torch around the foreground.

The second technique involves using a lens with greater focal length or Zoom. The far end of a mid level zoom range would suffice (60mm or 120mm 35mm equivalent) or, if available, a high end zoom lens allowing anything up to 200/300mm (400/600mm 35mm equivalent).

Once again manually set the focus to infinity and use a 30s exposure time. Train the camera/lens on an area of sky alone and fire away as and when you feel. To start, concentrate on an area of north-east sky near the Perseids radiant (see Perseids section) but do vary the location all around the sky.

Pros – Captured meteors will fill the frame with great detail (and colour).

Cons – Low success rate of meteor capture (due to small area of sky concentration)

In addition, do experiment by adopting the 15s continuous shooting technique with a zoom lens. This will also increase capture odds. Personally, I shoot with two cameras using both these techniques to really maximise the odds of capture, composition and detail.

The Perseids are meteors which appear to originate from a point within the constellation of Perseus in the north-eastern sky. This point, known as the shower’s radiant is a good starting point for aiming the camera lens. Do note that one might see a meteor anywhere in the sky but the direction of motion, when traced back, will point to the radiant. A meteor that does not point back to the known radiant for a given shower is not considered part of that shower. Locating the Perseids’ radiant is very simple and situated in the constellation Perseus, just below the familiar ‘W’ of the constellation of Cassiopeia.

Finally, it is worth making a quick point about Iridium Flares. Sometimes it is hard to tell the difference between an Iridium flare and a meteor. (See top photo). Iridium Flares are common communication satellites which illuminate when the sun reflects off their bright antennas. Usually the brightness, colour and trajectory are a giveaway (noticeably brighter in the center and dimmer at its ends). Iridium flares can also be accurately predicted (http://www.heavens-above.com) and which is the best indicator for confirming, as long as you note the time, direction and elevation.

This is one of the most prolific meteor showers and is associated with the comet Swift-Tuttle. During the peak of the perseids, the radiant (the place the meteors appear to come from) often seems to be the ‘sword handle’ within the constellation of Perseus.

(the above image was taken using the iPhone app Star Walk)

The Perseid meteor shower peaks on 12/13 August every year and can have anything from 80 to 140 meteors an hour. Observers have been known to describe Perseid meteors as being fast and bright in appearance. Often a large number of them leave a trail behind them as they enter the Earths atmosphere and in the past many of them have turned into fireballs.

It wasn’t until 1866 that the association with Comet 109P/Swift-Tuttle was proved by Giovanni Schiaparelli. The Perseid meteor shower itself has been known and observed for a long time. The first known recorded accounts were by the Chinese in AD36. Both the Japanese and Koreans also have documentation of observing the Perseids from the 8th century onwards. Western observations seem to start during the 19th century, or at least the ones that were documented.

Now with advances in technology we can watch the meteor shower (Moon dependent of course this year) from the comfort and warmth of our own living rooms. We can track who has seen meteor showers by using a twitter map and discuss in real time if any of our online friends spot a fireball. Modern technology gives us new ways to interact with other astronomers, and not just locally, it allows us to encourage others to get out in the back garden and just look up.

This month sees the most reliable meteor shower of the year; the Perseids. You can begin watching for Perseid meteors now, and the shower will last until mid-August, but the peak of the shower occurs in the small hours of Saturday 13 August 2011.

Perseus under dark skies

Perseus under moonlit skies

Unfortunately this year’s shower will be obscured by the full Moon which occurs on the same day, and so it won’t present its usual excellent display.

The number of meteors that you will observe every hour depends on a number of factors:

the density of the cloud of dust that the Earth is moving through, that is causing the shower in the first place;

the height above the horizon of the radiant of the shower, the point from which the meteors appear to radiate;

the fraction of your sky that is obscured by cloud;

the naked-eye limiting magnitude of the sky, that is a measure of the faintest object you can see.